100 lines
2.4 KiB
C
100 lines
2.4 KiB
C
/*
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* drivers/s390/char/sclp_quiesce.c
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* signal quiesce handler
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*
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* (C) Copyright IBM Corp. 1999,2004
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* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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* Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/cpumask.h>
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#include <linux/smp.h>
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#include <linux/init.h>
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#include <asm/atomic.h>
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#include <asm/ptrace.h>
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#include <asm/sigp.h>
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#include "sclp.h"
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#ifdef CONFIG_SMP
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/* Signal completion of shutdown process. All CPUs except the first to enter
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* this function: go to stopped state. First CPU: wait until all other
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* CPUs are in stopped or check stop state. Afterwards, load special PSW
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* to indicate completion. */
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static void
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do_load_quiesce_psw(void * __unused)
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{
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static atomic_t cpuid = ATOMIC_INIT(-1);
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psw_t quiesce_psw;
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int cpu;
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if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) != -1)
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signal_processor(smp_processor_id(), sigp_stop);
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/* Wait for all other cpus to enter stopped state */
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for_each_online_cpu(cpu) {
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if (cpu == smp_processor_id())
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continue;
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while(!smp_cpu_not_running(cpu))
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cpu_relax();
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}
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/* Quiesce the last cpu with the special psw */
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quiesce_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
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quiesce_psw.addr = 0xfff;
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__load_psw(quiesce_psw);
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}
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/* Shutdown handler. Perform shutdown function on all CPUs. */
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static void
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do_machine_quiesce(void)
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{
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on_each_cpu(do_load_quiesce_psw, NULL, 0, 0);
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}
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#else
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/* Shutdown handler. Signal completion of shutdown by loading special PSW. */
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static void
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do_machine_quiesce(void)
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{
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psw_t quiesce_psw;
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quiesce_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
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quiesce_psw.addr = 0xfff;
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__load_psw(quiesce_psw);
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}
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#endif
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extern void ctrl_alt_del(void);
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/* Handler for quiesce event. Start shutdown procedure. */
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static void
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sclp_quiesce_handler(struct evbuf_header *evbuf)
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{
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_machine_restart = (void *) do_machine_quiesce;
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_machine_halt = do_machine_quiesce;
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_machine_power_off = do_machine_quiesce;
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ctrl_alt_del();
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}
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static struct sclp_register sclp_quiesce_event = {
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.receive_mask = EvTyp_SigQuiesce_Mask,
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.receiver_fn = sclp_quiesce_handler
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};
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/* Initialize quiesce driver. */
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static int __init
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sclp_quiesce_init(void)
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{
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int rc;
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rc = sclp_register(&sclp_quiesce_event);
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if (rc)
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printk(KERN_WARNING "sclp: could not register quiesce handler "
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"(rc=%d)\n", rc);
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return rc;
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}
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module_init(sclp_quiesce_init);
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